236 Annals Entomological Society of America [Vol. X, 



Ri and R2+3; further branches of radius (both tracheae and 

 veins) are entirely wanting. In the adult wing of the European 

 Scoliaida, the separation of vein Ri occurs at the point of origin 

 of trachea Ri, which is very near the base; otherwise the 

 tracheation of radius, as far as persistent, is similar to that of 

 the pupal wings of A', platanella. 



Media. — In all species of Nepticula, media is represented by 

 an unbranched vein which reaches the wing margin below the 

 apex. In the pupal wings of both species examined, a single 

 trachea extends from base to wing margin, with no discernible 

 trace of branching. In N. platanella, the basal portion of this 

 trachea lies within the same vein cavity and alongside of the 

 base of the cubital trachea, from which it diverges to pass 

 obliquely to radius just beyond R2+3, lying alongside of and 

 in the same vein cavity with the radial trachea to beyond the 

 middle of the wing where it again diverges before the separation 

 of veins R4 and R5, and passes to the margin of the wing below 

 the apex. In one specimen (Fig. 2), at an earlier stage of 

 development than that shown in Figure 1, and in which the vein 

 cavities were not as well defined, the medial trachea does not 

 approximate as closely to cubitus at its base, nor to radius in the 

 middle of the wing, so that the relative positions of the basal 

 stems of the main tracheae approach more nearly to those of 

 the hypothetical type. In N. rosaefoliella, the trachea of media 

 lies alongside of and in the same vein cavity with radius from 

 the base of the wing to its point of divergence from R4+5 beyond 

 the middle of the wing. An intermediate condition is to be 

 noted in N. variella, where media coalesces with cubitus at 

 base, but passes to radius before the point of separation of Ri. 



Because of the unbranched condition of the medial trachea 

 it is impossible to determine with certainty the homology of the 

 vein which it precedes. 



In Obrussa and Glaucolepis media is two-branched; in the 

 former genus, the separation of the branches occurs beyond the 

 separation of media from R4+5 ; in the latter before the separation 

 of media from radius. In Obrussa, the trachccc in the imaginal 

 wing are not sufficiently persistent for study. In Glaucolepis, 

 the medial trachea is unbranched and shrivels up near the point 

 of separation of the first of the two branches of media. How- 

 ever, as all of the branches of the radial trachea are distinctly 



